There is about 80 091.88 km2 including 25
counties (cities) in the Yulin and Yanan regions of the north of Shaanxi
province of the loess
plateau. Exceptionally severe soil erosion is the most outstanding character in the area. And its
features are as follows: (1)Based on several circles of ancientry erosion in geology history, the
erosion of modern times is succeeded and more quickly developed. (2) The area of soil loss is
very big accounting for 76% of total land, intensity of river
sediment from erosion is very high
with annual transport sediment 6.96108 t in average. Erosion modulus by the data of hydrology
station of river is about 9 370 t/km2a. The channels or vales average density is 3.06 km/km2
with 45%55% of total area. (3) It is the very distinct for distributing law of type, manner and
intensity of soil erosion in vertically along the altitude and horizontally on the latitude. (4)The
close correlation between the erosion and the factors of the ecological environment. (5) The soil
loss becomes more severe because of building roads and factories, exploit coal mine and so
on. In order to developing the economic and rising the living standards of the people , we have
to take the
synthetizing measures for controlling soil loss.